This invention relates generally to single or multiple stage mechanical drive apparatus for rotating a shell-type roll, such for example as a suction roll or a deflection-compensated roll of the type utilized in paper machines, whereby the shell of the roll is rotated through a transmission to which power is introduced at the input shaft thereof.
Drive apparatus for rotating shell-type rolls of the type discussed above, are, of course, known. Thus, for example, a typical mechanical drive currently in use in connection with rotating a suction roll is illustrated in FIGS. A and B. It is understood that drive apparatus substantially equivalent to that shown in FIGS. A and B are utilized in the rotation of the roll shells of deflection-compensated rolls.
The initial criteria in the design and dimensioning of suction rolls is the minimum diameter of the tubular suction shaft which extends longitudinally through the interior of the shell. Typically, such tubular suction shafts have relatively large dimensions due to the relatively high air flow requirements and for this reason the diameter of the tubular suction shaft necessarily requires that the transmission for rotating the roll have relatively large dimensions at least in the radial direction.
Typical conventional drive apparatus such as that illustrated in FIGS. A and B, described in greater detail below, have the recognized drawback that the tubular suction shaft which houses the suction box of the suction roll within the roll shell must be supported over a relatively large length. As a consequence, the deflections of the roll are relatively large creating correspondingly large flexural moments. Another drawback of the conventional drive apparatus is that the elements which support the tubular suction shaft in the case of a suction roll or the massive axle which extends through the roll shell in the case of a deflection-compensated roll, and the housing for the transmission have comprised separate components which is disadvantageous for the reason, among others, that the apparatus is quite heavy and complicated in manufacture.
Still another drawback of conventional drive apparatus of the type illustrated in FIGS. A and B is that the drive apparatus requires relatively large spacial accommodations at least in the radial direction of the roll.
Still another reason why conventional drive apparatus of the type illustrated in FIGS. A and B have proven to be not entirely satisfactory is that the gear transmission is typically located at a position which is remote from the bearing location wherein the roll is rotatably mounted thereby tending to even further increase the magnitude of the roll deflections during operation.